Invasive Alien Vines Affect Leaf Traits of Riparian Woody Vegetation

Abstract

The vines Echinocystis lobata and Parthenocissus quinquefolia are spreading over the natural vegetation in riparian zones, which may significantly affect riparian vegetation properties and the quality of litter for aquatic organisms. We examined leaf morphological, biochemical and optical traits of these invasive alien species, each paired with its host, the willows Salix caprea and S. fragilis, respectively. The vines altered the host radiation environment and the amount of photosynthetic pigments. Both vines had significantly higher specific leaf area and lower leaf tissue density compared to the willows, even though the leaves of P. quinquefolia were significantly thicker. Leaf optical properties varied significantly between vines and willows in some spectral regions. Compared to the willows, the vines reflected less light as UV, and more as green, and transmitted more light as green, yellow and red. The overgrowth of the willows with vines affected the reflectance of the willow leaves. Redundancy analysis of the relationships between leaf biochemical traits and reflectance spectra showed that chlorophyll a, anthocyanins, and UVB- and UVA-absorbing substances explained 45% of the reflectance spectra variability, while analysis with morphological traits revealed that specific leaf area, leaf thickness and upper cuticle thickness explained 43%. For leaf transmittance, UVB- and UVA-absorbing substances, carotenoids and anthocyanins explained 53% of the transmittance spectra variability, while analysis with morphological traits revealed that specific leaf area explained 51%. These data show that invasive alien vines can be discerned from each other and their hosts by their spectral signatures. In addition, the differences in the leaf functional traits between the vines and their hosts indicate significant differences in the quality of the plant litter entering the river.

Morphoanatomical Characteristics in Riparian Vegetation and Its Adaptative Value

“…Invasive exotic plants have a negative impact on native riparian species, mainly because they affect the flow of energy and the cycling of matter, as well as by their excessive use of resources. A study on Echinocystis lobata and Parthenocissus quinquefolia (invasive climbing species) growing on Salix caprea and S. fragilis, respectively, showed that in both willow species the leaf cuticle became thinner relative to that of plants that grew without these vines [90]. This is a disadvantage since the cuticle contributes to the mitigation of the adverse impact caused by both biotic and abiotic stressors.…”

The Relationships of Habitat Conditions, Height Level, and Geographical Position with Fruit and Seed Traits in Populations of Invasive Vine Echinocystis lobata (Cucurbitaceae) in Central and Eastern Europe

“…Some experiments have shown that climbing plants generally colonise nutrient-rich patches of soil much more quickly and with much less investment in root biomass than trees [3]. Consequently, climbing capacity is considered an important factor facilitating the invasion success of alien plants in forest communities [7][8][9]. There are some interesting similarities and differences between native and non-native climbing plants in patterns of distribution and seed dispersal.…”

“…Biological invasions are one of the most serious threats to biodiversity and cultural heritage in the world [22,23].Studies on the impact of habitat conditions on the production and dispersal of seeds in invasive alien plants allow a better understanding of their geographical distribution [24] and adaptability to new habitats [9], as well as enable the identification of habitats particularly sensitive to invasion [25]. Plant height, seed weight, and seed morphology are some of the most important traits influencing abiotic seed dispersal [26].…”

Relationship between Environmental Conditions and Structure of Macroinvertebrate Community in a Hydromorphologically Altered Pre-Alpine River

“…It minimizes erosion and provides shade and shelter [8,10,11,14], but must have sufficient width and structure [14]. Where this vegetation has been destroyed, or the bank-structure has been changed, the riparian zone is frequently invaded by alien species [10,11], which establish thick stands and change its functionality [15]. The vulnerability of riparian zones to invasion of alien plant species (IAS) depends on its structure [16,17], i.e., its width, connectivity and vegetation composition.…”

“…The vulnerability of riparian zones to invasion of alien plant species (IAS) depends on its structure [16,17], i.e., its width, connectivity and vegetation composition. Human alterations of the riparian zone change abiotic factors such as substrate types, concentration of oxygen, pH and water temperature [18,19] as well as interactions between organisms [15,20]. Alteration of the flow regime cause serious degradation of riverine ecosystems [21].…”